Commutator for polyphase currents.



No. 882,682. PATENTED MAR. 24, 1908.

A. HEYLAND. GOMMUTATOR FOR POLYPHASE OURRENTS. PPPPPPPPPPPPPPPPPAN.21.1903.

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PATENTED MAR. 24, 1908.

A. HEYLAND. OOMMUTATOR FOR POLYP'HASE GURRENTS. APPLIQATION FILED JAN.21. 1903.

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A. HEYLAND. OOMMUTATOR FOR POLYPHASE OUBRENTS. APPLICATION FILED JAN.21. 1903.

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A. HEYLAND.

OOMMUTATOR FOR POLYPHASE GURRENTS. APPLIOATION FILED JAN. 21. 1903.

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No. 882,682. PATENTED MAR. 24.1908.

A. HEYLAND.

GOMMUTATOR FOR POLYPHASE GURRBNTS.

APPLIOATION FILED 3111.21. 1903.

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in Commutators fonPolyphase employed for the of such devices heretoforeknown has 1n-- volved current losses which exist throu hout Toall whomit may concern: L) Be it known that I, ALEXANDER Harman,

periodicity or into a current In the latter case the periodicityALEXANDER HEYLAND, OF BRUSSELS BELGIUM.

com'ra'ron ron ronmasn ctmmizr'rs.

' Specification Letters Patent.

' PatentedKu-eh 24, 1905.

Application filed January :1, 1m. semi no. 140,025.

a subject of the German Em ror, residing and having my post-office adress at 32 Rue du Marteau, Brussels, Be 'um, have 'in-. vented certainnew and usefu Im rovements which the following is a specification.

The purpose of acommutator for pol phase currents is to transform acurrent 0 a given direction. is zero. complish these results manner thanwhen the present invention is reason that the operation Existingcommutating, evic'es acthe operation as will behereinafte'r'set orth.With an ideal polyphase commutator the commutated (transformed) currentshould be a regular polyphase current, with a periodicity correspondingwith the relative speed (Ell? of the commutator. The'contra E. M. andthe ap arent losses in volt-am peres (not consi ering the ohmic losses)should increase or decrease in the same ratio as the transformedperiodicity.

In the United States Patent No. 510,534 is proposed for this purpose adirect current winding with direct current commutator. With thisarrangement I obtain in thedirect current windin the periodicity of whicisgiven by the perio-l dicity of the current in the brushes and the:slip of the commutator.

phase current. At

which is connected with the two segments, changes in direction. theseparate sections of the windings olyphase currents of a much higherperiodicity than the periodicity of the current in the brushes and thisperiodicity will increase in the same proportion as the number ofcommutator segments per pole increases. By the rotation of thecommutator thecurrent is supplied to or taken from continually changingpoints of the windings and this 1s the reason why other polyphasecurrents circulate in the windings, the periodicity of which is higherthan that of the current in the brushes and increases in the same ratiourrents, of

periodicity into a current of another' with a constant but in a lessefficient a polyphase current,

The total current: in the winding however is not a regular poly-l themoment the brush moves from one commutator segment to the next thecurrent in the section of the winding,-

Therefore I get in as the number of brushes or the number of.

phases of the current in the brushes increases. he result is that allthese currents with high periodicity produce contra E. M. F. which maybecome im ortant and prevent a perfect transformatlon from oneperiodicity into the other.

In my United States application Serial No; 93,763 filed Feb. 12, 1902 toobtain a short circuited armature to which, by means of commutator andbrushes, singleor polyphase current may be supplied, I proposed to makeuse of any wlnding with commutator, the se ments of which are connectedby means 0 connections of a certain resist- The mfluence of thesesegment con-- ance. nections is that they su press all currents of ahigher periodicity an therefore every extra contra E. M. F. and that thewindin carries really regular polyphase current. These connectionshowever meet with some theoretical and practical disadvantages. Theyalways form a shunt connection with the brushes and thgefore cause aninevitable loss of brush current which does not enter into the winding,the segment connections. By certain practical arrangements, forinstance: with open windings by certain pro ortions between the width ofsegments an brushes, I it will be ossible to reduce extent, that they donot influence on the. efficiency. But they always meet with practicaldifliculties, es ecially with multipolar machines with a hig number ofturns and a high resistance. easy to see that thev'v-indings dividethese segment connections in a'number of parallel groups equal to thenumber of poles of the machine. The resistance of each connectiontherefore has to 'ncrease with the number of parallel groups, 6. e. withthe number of poles of the machine. In many cases this leads to longresistances of small section, the securing of which on the commutator isdifficult.

' The present arrangement has for its object to avoid both difficulties,and to suppress partly or entirely the segment connections. In thedrawings, Figures 1 to 17 are diagrammatical figures representingdifferent windings and connections as more fully explained hereafter.

The object is to give the winding connected with the commutator thecharacter of a short circuited winding as for instance a squirrelcagewinding. his is obtained by any arbut finds its way throughthese lossesto. such an;

have an important It is rangement, which avoids the interruption or,

commutation of the current inthe section of the winding between the twosegments as the brushes go from one segment to the other. This result isobtained by alternately closing the sections of the winding connectedwith the commutator by the main brushes and during the period ofinterruption of these brushes by auxiliary circuits, which have acertain resistance to avoid a short circuitin during the interruptionperiod, and whic work only during the time that the corresponding mainbrushes are not directly in contact with the-commutator segmentsconnected to the windi During the remainin time these brushes areinactive and it will t erefore be possible to reduce to any amount theinfluence of the shunt connection of this auxiliary circuit. I

Generically stated, the invention consists in a.commutator com risingelectricallyinsulated sections,to w 'ch a winding is con nected andcurrent collecting devices bearing upon said commutator, the currentcollecting devices being so spaced about said commutator with re mutatorsections that a section of said commutator to which a winding connectionis made will come into connection with one current collecting devicebefore it leaves connection with the preceding one. By this means thewinding is continuously connected through the current collecting devicesand its circuit is never broken. It is to be understood that thesections of the commutator just referred to may each consistof a singlecommutator segment or may consist of several commutator segmentsconnected together as by resistances. It is also to be understood thateach current collecting device referred to may consist of a single brushor of a plurality of brushes electrically connected to ether as byresistances.

V ig. 1 represents the former case, as described in my former inventionwhere all the segments are interconnected by the connection 7 r r. Iconsidered here for its simplicity a bipolar threephase winding withthree brushes. The commutator must have at least six segments to avoid adirect short circuit between two brushes. If the winding is onlyconnected with three arts of the commutator I would obtain t eeintermediate segments, which are not connected with the winding. Itwill, of course, be possible to connect the windin also with thesesegments and I obtain t en alwa s more segments than brushes. To reducet e time of interruption of the winding section between two segments, asrepresented in Fig. 1 it will be suitable to make the Width of thebrushes nearly the same as the width of the intermediate segments. Thetime ofinterruption of the winding w will then be a minimum. In theposition Fig. 1

ation to the length of the comthe winding w w w is closed at the sametime by the brushes 1 2 3 and the se ent connections r r 1' r. Inposition i. 1 the winding, or at least part of it, is on y closed by thesegment connection 1' r r rand would be entirely open, if I suppress thesegment connections.

Fig. 2 sh0Ws that it is not necessary to connect all the segments, butonly so many that the winding sections are constant] directly orindirectly closed and that it wi 1 be possible to avoid a constant shuntconnection between two brushes. This is represented in Fig.2. Thecommutator has onl the three connections r r r. In the 081- tion a thewinding is directly closed by the three brush circuits; in position bby' the. segment connections and brushes in series: for instance. ww isclosed by 1' and the brush 1, 'w by r and brush 2, and w by r and brush3. The segment connections form no shunt Whatever with the brushes. Ashunt connection with the brushes will only exist in the intermediateposition between a and b, and this moment can be shortened as much as Ilike by a suitable width of brushes and segments, andif necessaryb alarger number of segments. Finally 1t wil be possible to suppress thesesegment connections entirely, if I onl ta e care by other means to keepthe wind ing sections constantly closed. If I do not want to use se mentconnections, this can be done by t ree auxiliary brushes, interconnectedby means of resistances directly; or indirectly, 'i. 8. connected withthe main brushes by means of resistances, as indicatedin Fig. 3. Insteadof only one set of auxiliary brushes it will be possible to employ twoor more sets, as indicated in Figs. 7 & 8, to obtain amost regularworking. It is also possible to substitute the main brushes by two ormore brushes connected by resistances.

The use of auxiliary brushes to suppress the segment connections has theadvantages that the resistances between the brushes, which serve thesame purpose as the segment connections before, can be easily fixed andregulated, and fulfil the object of reducing the losses in-a perfectway.

The winding is constantly closed, either through themain brushesdirectly or through the auxiliary resistances, without any short circuitbetween the brushes. This arran ement is not to be confounded withsimilar looking ones, where auxiliary segments are, by means ofresistances, connected with the main segments of the commutator, orauxiliary brushes are connected, by means of 125 resistances, with themain brushes, for the purpose of avoiding the sparking on thecommutator. There the auxiliary resistances are introduced for thepurpose that the interruption on the commutator segments 130 connectedwith the winding may take place radually. Here the auxiliary circuitsormed by the resistances have the opposite object 11. e. to avoid thecurrent'interruption on the commutator segments connected with thewinding. This maybe seen from the following fact. to introduce graduallythe current interruptions on the'commutator the auxiliary segments orbrushes follow the rotation with regard to the main segments or mainbrushes, while with my arrangement they :an also be placed in oppositedirection, as is indicated for instance in Figs. 2 and 3.

The characteristic feature of the arrangement is the fact that theauxiliary circuits must always be arranged in such way, that they avoida current interruption on the segments connected with the winding.

For a better understanding I have representeddiagrammatically in Figs.4, 5, 6, 7 & 8 same characteristic positions. w represents in general awinding of any kind, open or closed, ring or drum, or polyphase.

In the osition represented in Fig. 4, the current 0 the segment a can gothrough the brush 1, as well as through the resistance 1' and the brush2. A short-circuit between the brushes 1 and 2 is avoided by theresistance r. An instant later the brush 1 leaves the segment a and thecurrent of the segment a flows through the brush 2 only. With furtherrotation of the commutator the same phenomenon takes place with thesegment a and the brushes 2 and 3, etc. etc.

In Fig. 5 the current of the segment a can flow as well through theresistance '1" (left hand side) and the brush 1, as through theresistance r (right hand side) and the brush 2. The short circuit and 2is avoided by the two resistances r 1'.

An instant later the contact of the brush 1 through the resistance rwith the segment a is interrupted and the current flows through thebrush 2 only.

With further rotation the same phenomenon takes place between thesegment a and the brushes 2 and 3, etc.

The same phenomena occur with the arrangements in Figs. 6, 7 & 8.Instead of the segment connections 1' r the brush connections 1" 1' arethe acting parts.

In a similar manner to that employed in connection with the segmentconnection, the main brushes may be connected with preceding aswell asfollowing auxiliary brushes and if desirable a greater number ofauxiliary than main brushes may be employed. Finally it will be possibleto connect the same auxiliary brushes with several main brushes, as wellas to interconnect partly or entirely all the auxiliary brushes. It willalso be possible to subdivide the main brushes into two or a greaternumber of brushes connected with resistances.

I shall always obtain the same result,

With the arrangement.

between the brushes 1 formed and it will be sufficient to interconnectsym-.

metrically placed segments (Mordey connections), in such way, thatthrough these connections the segments connected with the winding aredirectly or in iirectly connected with the brushes.

Such a sixpole commutator is for instance represented in Figs. 9 and 10in which a 'c c are here the Mordey connections. Both the segmentconnections as well as the brush connections, are indicated and it willbe possible to use these simultaneously, or by means of suitablemodifications, suppress the brush connections or the segment connectionsand use the one orthe other alone. The arrangement has a specialadvantage for machines, as described in my United States application,Serial No. 93763 and has, with regard to the there proposed arrangement,the advantage of making a shortcircuitedarmature with a constantlyclosed winding, where constant losses of the brush current can beavoided and where circuit-resistance of the windings may be much lessthan was the case in the former arrangement.

The arrangement can be used as well for transforming poly hase currentsinto polyphase currents 0 another periodicity, as well as into a current'of constant direction, as well as into singlephase current; in the sameway it can be used for the o posite urposes in the'described way, asweil as by interchanging stationary and for the described purpose aswell as for other purposes. These four cases are illustrated in Figs.11, 12,13, and 14. Fig. 11 shows a commutator for a two phase winding.In Fig. 12 one phase is left out and the transcurrent in the winding 11)will be a single phase alternating current of a lower periodicity. If Imake the commutator rotate synchronously, the windingw will carry acurrent of constant direction (direct to the commuthe average short-,

moving parts,

35 only of said sections, and current collecting i and brushes, circuitsconnected to a portion fmodifications indicated in Figs. 15, 16 and 17.All these are characterized by the fact that the winding connected withthe commutator or parts of it are constantly closed in themselves byalternatively changing cirj cuits.

Instead of being placed on the rotor, the windin s-can be put on thestator in which case t e functions of commutator and brushes arereversed. Besides, all the previously known arrangements to avoid sparkling at the commutator can be used in connection with the above describedarrangel ment. The wiring can be used for alternating currents of anyperiodicity and for windings of any polarity.

It Will be obvious that the connections of the circuits may be differentfrom that shown in the drawings. Other circuits than the windings of themachine, as for instance the external circuit, may be connected to thecommutator while the windings may be connected to the brushes.

Numerous other modifications of the corinections of the circuits to thebrushes and commutator, which will be readily ap lied by persons skilledin the art and whlc do not de art from the spirit of this invention, miht be enumerated.

laims.

1. In. a dynamo electric machine, the combination with a commutatorcomprising electrically insulated sections arranged in the circumferenceof a circle, of a winding having a plurality of connections to a partdevices bearing upon said commutator, sai current collecting devicesbeing so spaced about said commutator with relation to the length of thesaid sections that a section of said commutator to which a given windingconnection is made, comes into connection with each of said currentcollecting devices before the connection with the precedingcurrentcollecting device is broken.

2. The combination ing relative movement of said commutator with acommutator, of brushes bearing thereon, means for causof the segments ofsaid commutator, and resistances connecting said circuits to the brusheswhen the latter bear on se ments not connected with said circuits anintermittently connecting segments to which said circuits are connectedas the brushes and commutator are relatively moved, substantially as andfor the purpose described.

3. The combination with a commutator, of brushes bearing thereon, meansfor causing relative movement of the commutator and brushes, circuitsconnected to a portion of the segments of the commutator, andresistances connecting said circuits to the brushes when the latter bearupon segments not connected to said circuits and intermittentlyconnecting said brushes together, substantially as described.

4. The combination with a commutator, of brushes bearing thereon, meansfor causing relative movement of the commutator and brushes, circuitsconnected to a portion of the segments of the commutator, andresistances connecting said circuits to said brushes, when the latterare bearing on segments not connected to said circuits, andintermittently connecting the segments with which said circuits areconnected.

5. The combination with a commutator, of windings connected thereto,brushes bearing upon the commutator, auxiliary brushes bearing upon thecommutator, resistances connected to each pair of main and auxiliarybrushes, circuits connected with the main brushes, and means for causingrelative movement of the commutator and brushes, the brushes being ofsuch size and so arranged with relation to the commutator that thecircuits of said windings areconstantly closed through changing brushcircuits, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ALEXANDER HEYLAND.

W'itnesses:

GREGORY PHELAN, MAURICE CoRBEAU.

